Category: pyrazoles-derivatives

Cecchini, Martina Maya published the artcileMild catalytic oxidations of unsaturated fatty acid methyl esters (FAMEs) by oxovanadium complexes, Category: pyrazoles-derivatives, the main research area is catalytic oxidation unsaturated fatty acid methyl ester oxovanadium complex.

A selection of unsaturated fatty acid Me esters, namely Me oleate (C18:1), Me linoleate (C18:2) and Me linolenate (C18:3) has been oxidized under mild homogeneous catalytic conditions, using a series of oxovanadium(IV) complexes containing 4-acyl-5-pyrazolone donor ligands with different substituents on acyl residue. The main goal was to evaluate the catalytic role exerted by oxovanadium(IV) metal center, as precursor complex, in the selective oxyfunctionalization of carbon-carbon double bonds of these bio-renewable resources, as a greener alternative to more drastic processes currently used at the industrial level. The three substrates, oxidized using tert-butylhydroperoxide as main oxidant, with or without solvents, showed high conversions of starting materials and high selectivities in the formation of corresponding mono- di- and tri-epoxides, especially under solvent-less conditions. Investigations on a probable catalytic cycle mechanism operative in the tert-butylhydroperoxide oxidation of a simple FAME model substrate, have been performed by means of ESI-MS.

Applied Catalysis, A: General published new progress about Oxidation. 1691-93-6 belongs to class pyrazoles-derivatives, name is 5-Methyl-2-phenyl-4-(2,2,2-trifluoroacetyl)-1H-pyrazol-3(2H)-one, and the molecular formula is C12H9F3N2O2, Category: pyrazoles-derivatives.

Referemce:
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics

Hecht, Sidney M. published the artcileStructure determination of the N-methyl isomers of 5-amino-3,4-dicyanopyrazole and certain related pyrazolo[3,4-d]pyrimidines, Recommanded Product: 5-Amino-1H-pyrazole-3,4-dicarbonitrile, the main research area is pyrazoledicarbonitrile amino tautomerism; tautomerism aminopyrazoledicarbonitrile; pyrazolopyrimidine structure.

Addnl. data considered in abstracting and indexing are available from a source cited in the original document. The position of N substitution of 4-aminopyrazolo[3, 4-d]pyrimidine derivatives was studied by chem. and spectroscopic techniques, and structures were assigned to the pyrazole precursors of these compounds The more abundant pyrazole resulting from treatment of tetracyanoethylene with MeNHNH2 was 3-amino-4, 5-dicyano-1-methylpyrazole (I) on the basis of its conversion to a pyrazolo[3,4-d]pyrimidine identical with authentic 4-amino-2-methylpyrazolo[3,4-d]pyrimidine, rather than with the authentic 1-methyl isomer. The assigned structure was verified by x-ray crystallog. determination of I. Because I was not expected to be the more abundant pyrazole, a mechanism was proposed to account for its formation. 13C NMR and uv data for 3-amino-4,5-dicyanopyrazole indicated that 5-amino-3,4-dicyano-1H-pyrazole was the major tautomer.

Journal of Organic Chemistry published new progress about Tautomers. 54385-49-8 belongs to class pyrazoles-derivatives, name is 5-Amino-1H-pyrazole-3,4-dicarbonitrile, and the molecular formula is C5H3N5, Recommanded Product: 5-Amino-1H-pyrazole-3,4-dicarbonitrile.

Referemce:
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics

Hasany, S. M. published the artcileExtraction and separation of mercury from toxic elements arsenic, cadmium, antimony and thallium, and other metal ions, Computed Properties of 1691-93-6, the main research area is mercury extraction toxic element; arsenic mercury separation; cadmium mercury separation; antimony mercury separation; thallium mercury separation.

Extraction of Hg with 3-methyl-1-phenyl-4-trifluoroacetylpyrazolin-5-one in CHCl3 is described. Maximum extraction (97.3%) and a distribution coefficient (D) of 36.5 are achieved at pH 8. Among the anions tested, thiourea, thiosulfate, and cyanide mask the extraction of Hg. A solution of 0.2M KCN was the most suitable stripping agent for Hg. Decontamination data show that Hg can be separated from toxic elements As, Cd, Sb, and Tl and from other metal ions, i.e., Ga, In, Ge, Sn, Fe Ir, and Pt. A few separations of anal. and radiochem. importance are discussed.

Journal of Radioanalytical and Nuclear Chemistry published new progress about Toxicants. 1691-93-6 belongs to class pyrazoles-derivatives, name is 5-Methyl-2-phenyl-4-(2,2,2-trifluoroacetyl)-1H-pyrazol-3(2H)-one, and the molecular formula is C12H9F3N2O2, Computed Properties of 1691-93-6.

Referemce:
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics

Mundra, S. K. published the artcileSynergistic extraction of uranyl ion with acylpyrazolones and some oxo donors, Recommanded Product: 5-Methyl-2-phenyl-4-(2,2,2-trifluoroacetyl)-1H-pyrazol-3(2H)-one, the main research area is uranyl extraction acylpyrazolone oxo donor; thermodn extraction uranyl acylpyrazolone oxo donor.

Synergistic extraction of uranyl ion with acyl pyrazolones such as 1-phenyl-3-methyl-4-trifluoroacetyl-pyrazolone-5 (HPMTFP, pKa = 2.7), 1-phenyl-3-methyl-4-acetyl-pyrazolone-5 (HPMAP, pKa = 3.8) in combination with oxo-donors of widely varying basicities, [diphenyl sulfoxide(DPSO), TBP, or TOPO] was studied at various fixed temperatures The results indicate that the equilibrium constants of the organic phase addition reaction (Ks) with these donors follow the order of their basicities (Kh) viz DPSO(0.033) < TBP(0.16) ≪ TOPO(8.9) with their corresponding log Ks values for 3.40, 3.88, 8.05 for HPMTFP system and 3.52, 4.22, 8.04 for HPMAP system. The thermodn. parameters associated with the organic phase addition reaction with these systems were evaluated by the temperature coefficient method. The organic phase addition reaction with TOPO is stabilized both by entropy as well as enthalpy change in both the cases. The high neg. values of enthalpy and low values of entropy for the TBP system may be explained by the addition and not the substitution reaction for the water mols. in the metal chelate. Lanthanide and Actinide Research published new progress about Basicity. 1691-93-6 belongs to class pyrazoles-derivatives, name is 5-Methyl-2-phenyl-4-(2,2,2-trifluoroacetyl)-1H-pyrazol-3(2H)-one, and the molecular formula is C12H9F3N2O2, Recommanded Product: 5-Methyl-2-phenyl-4-(2,2,2-trifluoroacetyl)-1H-pyrazol-3(2H)-one.

Referemce:
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics

Veibel, Stig published the artcilePyrazole studies. VI. Variation of the basic properties of pyrazolones with substitution in the pyrazolone nucleus, Name: 5-Phenyl-1H-pyrazol-3(2H)-one, the main research area is .

cf. C.A. 48, 674g. pKB values were determined for a number of pyrazolones by titration with HClO4 in glacial HOAc. The compounds studied (R’s shown only when other than H), pKB, and m. ps. were: (I), 11.5, 165°; (II), R3 = Me, 10.9, 216-18°; (III), R3 = Me3C, 11.1, 200°; (IV), R3 = Me, R4 = Et, 11.1, 227-8°; (V), R3 = Me, R4 = C3H7, 11.2, 207-8°; (VI), R3 = Me, R4 = C3H5, 11.2, 195-6°; (VII), R3 = Me, R4 = Ph, 11.4, 208-10°; (VIII), R3 = Ph, 11.4, 232-3°; (IX), R1 = R3 = Me, 10.3, 117° (b19 130°); (X), R1 = R3 = Me, R4 = Et, 10.5, 94-5° (from EtOAc) (b15 137°); (XI), R1 = R3 = Me, R4 = C3H7, 10.5, 84-5° (from EtOAc) (b15 150°); (XII), R1 = R3 = Me, R4 = C3H5, 10.5, 71-2°; (XIII), R1 = R3 = Me, R4 = Ph, 10.9, 175° (from aqueous MeOH); (XIV), R1 = Me, R3 = Ph, 10.9, 206°; (XV), R1 = Ph, R3 = Me, 11.3, 127°; (XVI), R1 = Ph, R3 = Me, R4 = Et, 11.5, 111°; (XVII), R1 = Ph, R3 = Me, R4 = Pr, 11.4, 101-2° (XVIII), R1 = R4 = Ph, R3 = Me, 11.9, 199-200°; (XIX), R1 = R3 = Ph, 12.2, 137°; (XXa), R1 = Ph, R3 = Me, R4 = Cl, 13.2, 153°; (XXb), R1 = Ph, R3 = Me, R4 = Br, 13.3, 122°; (XXI), R1 = Ph, R2 = R3 = Me, 11.2, 113°; (XXII), R1 = Ph, R2 = R3 = Me, R4 = Me2CH, 11.6, 101-3°; (XXIII), R1 = Ph, R3 = Me, R4 = pyrazolonyl, 13.0, decompose; (XXIV), R1 = Ph, R3 = Me, R4 = 3-methyl-5-oxo-1-phenyl-2-oxazolidin-4-ylidenemethyl, 13.8, 185°; (XXV), R1 = Ph, R3 = Me, R4 = PhCH:CPh, 12.2, 220°; (XXVI), R3 = Me, R2 = R4 = Et, > 15, 104-5°; (XXVII), R1 = Ph, R2 = R3 = Me, R4 = Cl, > 15, 68°; (XXVIII), R1 = Ph, R2 = R4 = Et, R3 = Me, > 15, 161-2°; (XXIX), R1 = Ph, R4 = Me, 12.2, 167°; (XXX), R1 = Ph, R3 = Et, R4 = Me, 12.3, 172°; (XXXI), R1 = R4 = Ph, 12.9, 256°; (XXXII), R1 = Ph, R2 = R4 = Me, 11.6, 113°; and (XXXIII), R1 = Ph, R2 = OMe (at C3), R4 = Me, 12.5, b16 154-6°. Me3CCOCH2CO2Et (7.5 g.), 10 cc. EtOH and 4 cc. 60% N2H4.H2O allowed to stand 2-3 hrs. and filtered gave 4.2 g. III, recrystallized from aqueous EtOH. VII was similarly prepared in 27% yield from AcCHPhCO2Et (XXXIV). In the preparation of IX to XIV, a suspension of 1 mole Ba(OH)2.8H2O in 500 cc. H2O was heated at 100°, 1 mole N2H4.H2SO4 in 150 cc. H2O at 70° added, then 300 cc. H2O, the mixture stirred 1 hr. at 70% filtered, the BaSO4 washed with hot H2O, the combined filtrate and washings made up to 1 l. with H2O; heated with 0.2 mole α-substituted Et acetoacetate or Et benzoylacetate and 200 cc. N MeNHNH2 at 70° for various times, the solution extracted twice with ligroine, the H2O removed at 45-50° in vacuo from the aqueous layer, the residue taken up in CHCl3, dried with anhydrous Na2SO4, the CHCl3 evaporated, and the crude pyrazolone purified. The yields of IX to XIV were 51, 60, 65, 50, 70, and 65%, resp., and the reaction time 0.5, 10, 10, 5, 10, and 10 hrs. XXXIV (4 g.) and 2 g. PhNHNH2 heated 1 hr. at 140° gave 3.2 g. XVIII. XXV was prepared in 50% yield by heating equimolar amounts of 1-phenyl-3-methylpyrazolin-5-one 3-4 hrs. with PhCH2Bz, filtering, washing the product with Et2O, and recrystallizing from glacial HOAc. The dipole moments of XXXII and XXXIII were determined

Acta Chemica Scandinavica published new progress about Basicity. 27412-71-1 belongs to class pyrazoles-derivatives, name is 5-Phenyl-1H-pyrazol-3(2H)-one, and the molecular formula is C9H8N2O, Name: 5-Phenyl-1H-pyrazol-3(2H)-one.

Referemce:
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics

Saeed, M. Mufazzal published the artcileSynergic extraction of Eu(III) with 3-methyl-1-phenyl-4-trifluoroacetyl-2-pyrazolin-5-one (HPMTFP) and tribenzylamine (TBA) from perchlorate media, Recommanded Product: 5-Methyl-2-phenyl-4-(2,2,2-trifluoroacetyl)-1H-pyrazol-3(2H)-one, the main research area is extraction europium fluoroacetylpyrazolinone benzylamine aqueous perchlorate; formation constant europium complex synergic extraction; partition europium extraction fluoroacetylpyrazolinone benzylamine.

Synergic extraction of hydrolyzable lanthanide Eu(III) was studied at low pH range with 0.05 M (HPMTFP + TBA) in CHCl3 from aqueous perchlorate media. The composition of the adduct was established as Eu(PMTFP)3·TBA and Eu(PMTFP)3·2TBA under the conditions of 0.01 M ≥ TBA. The formation constants Ka, Ksyn1, and Ksyn2 and stability constants β1, β2, and K2 of the organic phase reaction were calculated Among the various anions and cations tested, fluoride, oxalate, phosphate, EDTA, Cu(II), and Ti(IV) have drastically reduced the extraction of Eu, whereas oxalate partially reduces the extraction

Radiochimica Acta published new progress about Anions. 1691-93-6 belongs to class pyrazoles-derivatives, name is 5-Methyl-2-phenyl-4-(2,2,2-trifluoroacetyl)-1H-pyrazol-3(2H)-one, and the molecular formula is C12H9F3N2O2, Recommanded Product: 5-Methyl-2-phenyl-4-(2,2,2-trifluoroacetyl)-1H-pyrazol-3(2H)-one.

Referemce:
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics

Katritzky, Alan R. published the artcileNovel chromophoric heterocycles based on maleimide and naphthoquinone, Quality Control of 27412-71-1, the main research area is heterocyclic dye pigment; halomaleimide condensation nucleophile; chloronaphthoquinone condensation nucleophile.

1-Phenyl-3,4-dichloromaleimide, 1-propyl-3-bromomaleimide, and 2,3-dichloro-1,4-naphthoquinone were condensed with nucleophiles such as pyrazole, 4-pyridone, imidazole, PhNHNH2, o-H2NC6H4OH, o-H2NC6H4SH, 1,2,4-triazole, benzotriazole, pyridine, etc., to yield a range of heterocyclic dyes and pigments, the visible absorption spectra of which were discussed.

Journal of Heterocyclic Chemistry published new progress about Dyes. 27412-71-1 belongs to class pyrazoles-derivatives, name is 5-Phenyl-1H-pyrazol-3(2H)-one, and the molecular formula is C9H8N2O, Quality Control of 27412-71-1.

Referemce:
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics

Shukla, J. P. published the artcileProtolytic equilibria of several 4-acyl-substituted 1-phenyl-3-methylpyrazol-5-ones in dioxane-water mixtures, Category: pyrazoles-derivatives, the main research area is ionization constant pyrazolone acyl derivative; solvent effect ionization acylpyrazolone; thermodn ionization acylpyrazolone; substituent effect ionization acylpyrazole.

Thermodn. proton ionization constants, pKa, of several 4-acyl-substituted pyrazol-5-ones I [R = CF3, Me, (CH2)4Me] were determined in various dioxane-water mixtures at 25 and 35 ± 0.1°. The pKa values were determined by glass-electrode potentiometry and refined by computer. Both extrapolation and least-squares methods were used to obtain pKa values in pure water. All three acyl derivatives are weak monoprotic acids with pKa values between 2.5 and 3.9, increasing in the order stated. The pKa values do not vary linearly with the reciprocal of the dielec. constant of the medium; however, a plot of pKa vs. the mole fraction of dioxane is linear at a given temperature Values of standard free energy, enthalpy, and entropy changes associated with their protolytic equilibrium were also calculated Temperature, medium and substituent effects are briefly discussed.

Journal of Physical Organic Chemistry published new progress about Enolization. 1691-93-6 belongs to class pyrazoles-derivatives, name is 5-Methyl-2-phenyl-4-(2,2,2-trifluoroacetyl)-1H-pyrazol-3(2H)-one, and the molecular formula is C12H9F3N2O2, Category: pyrazoles-derivatives.

Referemce:
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics

Earl, Robert A. published the artcileChemical and carbon-13 nuclear magnetic resonance reinvestigation of the N-methyl isomers obtained by direct methylation of 5-amino-3,4-dicyanopyrazole and the synthesis of certain pyrazolo[3,4-d]pyrimidines, SDS of cas: 54385-49-8, the main research area is pyrazole amino dicyano methylation; methylation aminodicyanopyrazole; pyrazolopyrimidine amino methyl.

The structural assignments for the isomeric N-1- and N-2-methyl derivatives of 5-amino-3,4-dicyanopyrazole obtained by direct methylation by C. L. Dickenson et. al (1964) were reinvestigated. The higher melting isomer was annulated to give 4-amino-3-cyano-1-methylpyrazolo[3,4-d]pyrimidine (I, R = CN), which with alkaline peroxide gave I (R = CONH2). Hydrolysis of I (R = CONH2) under more vigorous conditions gave I (R = CO2H), which was decarboxylated in hot sulfolane to give I (R = H). This established the structure of the N-methylpyrazole as 5-amino-3,4-dicyano-1-methylpyrazole and reversed the structural assignment previously reported. A similar reaction sequence converted the lower melting isomer into 4-amino-2-methylpyrazolo[3,4-d]pyrimidine (II) and established the structure as 5-amino-3,4-dicyano-2-methylpyrazole.

Journal of Organic Chemistry published new progress about Methylation. 54385-49-8 belongs to class pyrazoles-derivatives, name is 5-Amino-1H-pyrazole-3,4-dicarbonitrile, and the molecular formula is C5H3N5, SDS of cas: 54385-49-8.

Referemce:
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics

Sinru, Lin published the artcileAscending water electrode studies of metal extractants 4-acyl-5-pyrazolones and selected tervalent lanthanide ions, Formula: C12H9F3N2O2, the main research area is acylpyrazolone polarog ascending water electrode; water ascending stationary electrode acylpyrazolone; pyrazolone acyl polarog dichloroethane water; phenylmethyltrifluoroacetylpyrazolone polarog dichloroethane water; phenylmethylbenzoylpyrazolone polarog dichloroethane water; lanthanide acylpyrazolone polarog ascending water; complex lanthanide acylpyrazolone polarog.

The polarog. and chhronopotentiometric behavior of the chelating extractants 1-phenyl-3-methyl-4-trifluoroacetyl-5-pyrazolone and 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone in the dichloroethane-aqueous systems were characterized at the ascending H2O electrode and the stationary H2O electrode. The nature of the phase transfer processes both in the absence and presence of tervalent lanthanide metal ions was elucidated. Self-adduct and mixed ligand chelate formations were deduced (the latter when trioctylphosphine oxide is present). The reversibility, transfer coefficients, and transfer rate constants of the ligand anions were also deduced. This electrochem. approach is shown to provide novel insights into solvent extraction processes.

Analytical Chemistry published new progress about Electrodes. 1691-93-6 belongs to class pyrazoles-derivatives, name is 5-Methyl-2-phenyl-4-(2,2,2-trifluoroacetyl)-1H-pyrazol-3(2H)-one, and the molecular formula is C12H9F3N2O2, Formula: C12H9F3N2O2.

Referemce:
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics